This invention relates to tetrahydroquinazoline compounds and compositions containing the same which are useful for controlling insects in agricultural crops. Still more particularly, this invention relates to certain 2,4-diamino-5,6,7,8-tetrahydroquinazoline compounds and compositions, and their use as insecticides against a variety of insects, including larvae, such as the tobacco budworm. Numerous of these diaminotetrahydroquinazoline compounds employed herein, and their preparation, have been described in the literature for use in a variety of fields, but not as insecticides.